Pelvic inflamatory disease (PID) affects women in the United States in near-epidemic proportions. Nearly 11% of American women of reproductive age reported that they received treatment for PID in 1988. The costs associated with PID and its sequelae are enormous. Annual U.S. expenditures for the acute treatment of PID have been estimated at between $700 million and $2 billion annually; indirect costs may amount to an additional $1 billion per year. Inpatient treatment is over 10 times more expensive than outpatient treatment. The primary aim of thi study is to test the effectiveness and cost-effectiveness of outpatient vs. inpatient treatment for PID in preventing involuntary infertility. Additional long-term outcomes to be compared are repeat episodes of PID, ectopic pregnancy, functional decline due to chronic pelvic pain, frequency of health service use, the occurrence of indirect costs associated with PID-related illness, and patient-reported quality of life. This study is a randomized clinical trial involving adult female patients. During a 5-year period, 1,380 women will be enrolled from 6 clinical sites. A total of 1,200 women in seven clinical sites will be randomized in equal numbers into one of two treatment groups: inpatient or outpatient. Non-investigational antibiotics consisting of Cefoxitin and Doxycycline will be used in both groups, with a total treatment course of 14 days. Follow-up for each patient encompasses a period of 60 months.